Glass leer



Sept. 11.1928. 1,34,239

w. A. MORTON GLASS LEER Filed March 14. 1925 i 7 Sheets-Sheet 1 mmjtmmmmmmj \AQ\ U A TTORNEY Sept. 11, 1928. l,684;239

w. A. MORTON v GLASS LEER Filed March 14, 1925 '7 Sheets-Sheet 2 jaws! IZIZI@EIZ3 ATTORNEY INVENTOR.

Sept. 11, 1928;

W. A. MORTON GLASS LEER' Filed March 14 ,1 .1925

"7 Sheets-Sheet 4 A TTORNEY Sept. 11, 1928. 1,684,239

W. A. MORTON GLASS LEER Eihdwlhmh 14L 192 -'Z Shoots-Sheet 5 ATTORNEY Sept. 11, 1928, x 1,684,239

W. A. MORTON GLASS LEER wFiled. March 14,4925

7 Sheets-Sheet 6 Elm 2 21 2121 uzuzmzam ATTORNEY INVENTO 1,684,239 Sept 1928' w. A. MORTON emss LEER Filed March 714-1925 7 Sheets-Sheet '7 ATTORNEY i ables. the

Patented .sia. 11,192

UNITED, srn'rrz sv .PATENT OFFICE.

' HORTON COMPANY, 01 PITTSBURGH, PENNSYLVANIA, A CORPORATION OEQPENN- sY v'aNm j Application filed March 14, 1925, Serial No. 15,507.

This invention is for an improvement in glass leers, and particularly leers of the endess conveyor type.

In annealing glassware in annealing appao ratus of the class to which my invention relates, it is very desirable to introduce the ware to the annealing chamber at a temperature corresponding to the maximum temperature of the annealing chamber, and to gradually 4 reduce the temperature. of the ware from the f 7 point of introduction toward the point of discharge. Considerable difiiculty has been en- .countered in maintaining the entrance end of the leer at a high temperature, the maximum temperature usually being attained several feet back from the entrance. In recent installations, of leers using an endless conveyor, it has been the racticein certain instances to have the mu e of the leer overhang the forward or receiving end of the conveyor, and to provide flues in the overhang through which a large portion of the gases of combustion are drawn, to therebyheat the forward end of the leer.

- ever, the temperature increases gradually from-the entrance to a point several feet back of the entrance, but the int of maximum temperature is considera 1y nearer, the. en-

the maximum temperature obtained is considerably higher.

For instance, in the old style leer, having a mufiie of about fifty feet in length, the point of maximum temperature'was, on the average, between twenty and thirty feet back from the entrance, and the maximum temperature obtainable was little above 500 0., while the tween 30D and 400 C. 1 In muflles of shorter length, approximately the same ratio of max'-' imum temperature and distance obtains.

The present invention is for an improvement in the overhung type of leer, which enoser'to the point of entrance than be much in leers heretofore built and where n the amiss LEER. j

.Even. in this overhang type of jleer, how-.

trance of the lee} than in the old. style, and

temperature at the tpoint of introduction was the temperature atthe' point of entrance is bepint of maximum temperature to a Thety'pe of leer shown in Figs. 1 to 6 HEIISSUED ceding its entry into the mufiie, whereby heat absorption at the point of entry is materially dectgelased, and in some cases, entirely elimi- The advantages are obvious'to those skilled in the art. There'is, as has been proved in actual installations, a smaller percentage of breakage and a greater percentage of satisfactorily annealed articles. There is also a.

more efiicient annealing, as shown, of course, by the reduction inbreakage and increase in satisfactorily annealed ware, and there is an appreciable saving of fuel.

attained by the invention, which may be understood by reference to the accompanying drawings which illustrate desirable embodiments of the inventiori, but it will. be understood that various changes and modifications are contemplated within the spirit of the invention. In the drawings:

Fig. 1 is a longitudinal section through a tmuflie leer embodying one form of my invenion;

Fig. 2 is a divided-horizontal section partly in the plane of line AA of Fig. 1 and partly in the plane of line B-B of Fig. 1, the diviplane of section 13-13 on line (1-0 of Fig. 1;

Fig. 4 is a vertical transverse section on line IVIV of Fig. 1;

Figs. 5 and 6 are similar sections onlines V- V and VIVI of Fig. 1, respectively.

Fi 7 is a view similar to Fig. 10f a modified orm;

These and other objects and advantages are 3 Fig. '8 is a view similar to Fig. 2, showing sections on lines D-D and E-E of Fig. 7;

Fig. '9 is'a part elevational view .and a part transverse section on line IXIX of 7,; 10 is a similar section on line X p of Ig I I Figfll is a chart showing the characteristic temperature curves for the old style leer, the

overhung leer, and my improved leer, as plotted from installations now-in use. 7

elusive ma be first described. This is the,

usual over ung front type of leer, such for instance as that shown in United States Patent to Walter O. Amsler No. 1,533,298 of April 14, 1925, but having my improvement applied thereto. Much of the construction of the leer thus being old, the construction of the leer broadly need be only generally referred to.

In the drawing, 5 designates the outer side walls of a leer, having an arched top 6. The bottom of the leer is designated 7. Spaced from the top, side and bottom walls of the leer inside thereof is the muffle chamber 8, having a floor or bottom 9, side walls 10, and. an arched top 11, the walls of the muffle preferably-being constructed in the usual manner of paneled tiles.

Between the top of the muflle and the top of the leer is a combustion space that may be divided by a transverse partition 12 into a forward chamber 13 and a rear chamber 14. The usual vertical flues 15 are provided at the sides of the mufii'e. In the drawings, only those flues after the first three are designated 15, the first three being designated 15, and being hereinafter morefully described.

' The flues 15 open into the space 16 under the floor of the muflle, and in this space are suitably arranged bafiies 17. The space 16 may be divided by a transverse wall 18, so that the hot ases will flow from the combustion chamber down some of the flues 15, circulate under the bottom of the m'uflle, pass up into .the rear chamber 14, flow down other fthe passages 15, again circulate under the muflle, to the rear of wall 18,- and finally pass out of the rearmost vertical flues 15 into the main stack 19. The arrows in Fig. 2 indicate this up and down flow of gases through the several flues. This general arrangement is now incorporated in present forms of .leers.

A suitable burner 20 ma be provided at the top of the leer, and amper plates 21 may be provided in the several flues 15 for regula ing the flow of gases through the sev-.

eral fl es to control the temperature graduation, as will be understood by those skilled in the art.

in opening 5". Spaced back from the door is a shaft 22 having sprocket wheels 23 thereon over which an endless Jconveyon24 passes from its return movement under the floor of the leer in the mufile chamber. Along the bottom of the muflle chamber are guide rails 25 for this conveyor, of which, for the sake of clearness, only a small portion is shown.

As will be seen in Fig. 1, the front end of the leer and muflle overhangs the conveyor pulleys or wheels 23. In order to draw heat to thefront part of the muflle above and forwardly of the pulleys, or'entrance point of the conveyor, the first side flues, as for instance the first three side flues 15, are pro- In the front wall 5 of'the leer is a feedingvided, as in said patent of Walter O. Amsler. Of these, the foremost leads into a vertical passage 26 in front of the pulleys.

The next two flues, in order that there may be a draft therethrough, are joined at their lower ends with an opening into the first flue, as indicated by the dotted lines at 15 in Fig. 1,,and'as shown in the upper part of Fig. 2. By manipulation of dampers 21, the desired amount of hot gases from the combustion chamber may be directed through these for- Wardmost flues to draw heat to the forward or overhung portion of the muflie.

While I have mentioned three flues, it is for the purpose of illustration merely, as the number of flues so arranged is immaterial so long as they provide for drawing some of the heat to the forward part of the leer. Furthermore, the second two flues 15 could be joined to the first flue 15, as illustrated in the.

said Amsler patent, rather than joining with the first flue 15*, although the latter form is desirable. The point is that none of the side flues can be blind or dead-ended.

The vertical passage 26 narrows toward its lower end, and its lower end opens horizontally into the sub-structure 27, as shown in Fig. 3. This structure is ofa refractory con- 34, so that, after the flue passages of the leer have become hot enough to establish a draft, the gases passing through the sub-structure may be directed through ports leading up to and communicating with flues 15, so as to utilize all the available heat.

. It will be seen that the sub-structure 27 extends under the sprocket wheels 23, and under the conveyor, several feet back from the point where it entersthe leer. It is fully as-wide as the conveyor, and preferably has thin tile on its upper surface, over which the conveyor rides, so as to radiate a maximum of its heat 1 to'the conveyor. Just above the top of the 'sub structure are rails 35 to guide the return section of the conveyor below the bottom of the leer and, above the top of the sub-structure. Vith this arrangement, the returning portion of the conveyor, which travels at ya relatively slow speed, can be raised to approximately the temperature of the forward part of the leer." T-his is done, however, without sacrificing any of the heat available for heating the front end of the leer. In the said Amsler patent, the excess heat passing down the first flue is wasted, whereas in the present invention, it is utilized to its fullest extent.

guides for this conveyor being shown at 52. The conveyor is designated 53. Near the for- Not only does this arrangement heat the'con- "---ward" end of the mufile are sprockets 54.

veyor, but it heats the air around the con veyor, so that the air which enters the mufiie around the sprocket wheels and shaft is highly preheated.

The result of the invention may be readily appreciated by referring to Fig. 11, which is achart plotted against temperature measurements of actual leer installations of corresponding dimensions.

In the chart, which shows the temperatures of the muflie, line A is plotted against a leer of the Amsler or overhung type, modified to incorporate the present invention. The dotted line B shows the temperature curve of the usual Amsler or overhung type without the present invention. 'The dot-and-dash line C is the temperature curve of the usual type of endless conveyor leer without the overhung mufile chamber.

Line (lindicates that at the point of entry,

the temperature is about 100 C., and it increases quite gradually back from the entrance until the maximum of about 510 C. is reached, about twenty-six feet back in the fifty-foot r'nulfie. Line B shows that the temperature at the entrance point is considerably higher in the overhung type of leer, it being about 350 C. The maximum temperature of about 575 C. is rather gradually approached between eleven and thirteen feet back from the entrance. Line A shows the temperature at the entrance to be above 600 C., and that there is an increase from this point of only about 20 C., this maximum temperature point being less than six feet from the entrance. v

Curve A approaches a practically ideal condition for annealing glassware, and in practice, it has been found that the leer reduces breakage to a percentage far below any heretofore obtainable. The conditions are also ideally suitable for heat-resistant ware of the well known Pyrex type, and all heavy poorly distributed glasses.

In the construction shown in Figs. 7 to 10 inclusive, I have followed the same general idea adapted to a leer wherein the return of the conveyor travels partway through the mufile chamber to thereby become preheated.

In these figures, 4O designates the side walls, 41 the front wall, .and 42 the top of a leer construction. The muffle chamber is designated 43, and it has a top wall or roof 44,

side walls 45, and a bottom 46, which is considerably lower than the muffle bottom in the Fig. 1 construction. This bottom 46 is dropped below the level of the upper conveyor guides 47 and below the bottom 48 .of the annealing tunnel 49. Bottom 46 is extended at 50 under the bottom of the tunnel, and it is through the space or opening 51 that the return of the conveyor enters the mufiie, loyver around which the conveyor passes.

The mufile chamber is spaced from the walls ofthe leer, so as to provide the combustion chamber and side fiues as hereinbeforc 'tion circulate throughside ues in the man ner hereinbefore described. This heating chamber 55 has a longitudinal passage 56 therein which is separate and distinct from the remainingspace under the floor of the muflle.

At its forward end, passage 56 communicates with vertical passage 57 in the front I wall 41. Passage 57 communicates with side fiues 58 at the forward end of the mufile, and it is through these side flues that heat is drawn to the forward part of the mufiie chamber, as explained in connection with the leer ofthe type shown in Fig. 1. The rear of passage 56 terminates in spreading flues 59 that lead to the chimney 66. Only the first few of the side flues 58 communicate with paswith the heating chambers 55, as above men tioned. The last series of side flucs 59 also sage 57. Theother side flues 59 communicate lead to chimney 60. The arrows in Fig. 8 in dicate the general upand down flow of gases With this arrangement, the gases of combustion that heat the front of the mufiie through the side flues 58 serve to heat the center of the bottom of the muffle chamber. The advantage of the separate passage 56 is to ob tain a better control of the flow of hot gases to the several parts of the leer. This control of gas fiow can further be regulated by the provision of the usual dampers 61.

In this construction, the return portion of the'conveyor enters the muflie well back of the forward portion of the leer and is gradually preheated until it is at the temperature of the muflle when it reaches a position to receive the ware. As it is desirable to radually reduce the heat from the front of t e leer back, the

conveyor, entering the cooler end of the leer, assists, by its absorption of heat, in maintain ing this condition. The return portion of the conveyor, furthermore, moves close to the bottom of the muflle, and is heated to a very hi h temperature, and the gases that are used inIieating the forward end of the mufiie assist in heating the conveyor.

From the foregoing, it will be seen that have, by preheating the conveyor before bringin it into the top of the forward end of the mu e, made a remarkable improvement in leers, and have done this without greatly adding to the cost of the construction. The invention utilizes heat that has heretofore been wasted, so that,'besides giving. greatly Ill! " higher maximuin'temperatures, it effects a saving of fuel, in that more of the available heat is delivered to the muffler A What I claim is: I 1. In a glass leer of the muffle type having an endless conveyor for carrying wares therethrough, and in which the muflie over- ,hangs the forward end of the conveyor, said leer having passages for the circulation of gases around the sides and under the bottom of the muflle, other passages at the sides of the forward end of the muffle for heating the portion of the m'uflle overhanging and in advance of the conveyor, and a surface overand in close proximity to which they forward end of the return portion of the conveyor moves, and a circulating passage under said surface through which gases passing through the-said passages at the forward end of the muflle flow to heat the conveyor.

2. In a'glass leer, a mufiie, a conveyor having a portion extending through the muffle and a return portion below the muffle, the forward end of the conveyor entering the muffle a short distance back from the forward end of the muflie whereby the muffle overhangs the forward end of the conveyor, gas circulating chambers above and below the mufile and flues at the sides of the muffle connecting the upper and lower chambers, a separate flue at the sides of the portion of the muflie overhangingthe conveyor, and a substructure extending under the forward end of the return portion of the conveyor and below the muflie, and of substantially the same width as the conveyor, said substructure having a circulating chamber therein with which the said separate flues for heating the overhung portion of the muffle communicate, said sub-structure constituting a heating means for the conveyor.

3. In a muflle leer, of the type having an endless conveyor with the muflle passage overhanging the point where the returning portion of the conveyor enters the muffie, separate passagesat the sides of the muffle for heating that portion of the muffle which extends in advance of the conveyor and that portion of the muffle through which the conveyor passes, and a sub-structure under the conveyor having a circulating chamber therein heated from gases leaving those flues that heat the sides ofthe muffle in advance of the conveyor for heating said conveyor immediately in advance of where it enters the flues around the overhung portion of the muffle leadin from said upper chamber to the conveyor eating means, and flues at the sides of the muflle rearwardly of the point where the conveyor enters the muffle connect ing the upper chamber with thechamber below the muffle.

5. In a mufile leer having an endless conveyor passing through the muffle thereof and of the type in which the muffle extends forwardly beyond the forward end of the conveyor, gas circulating passages around the forward part of the muffle in advance of the forward end of the conveyor, other gas circulating passages around the sides of the muffle back from the forward end of the conveyor, and means utilizing gases passing through said first mentioned circulating flue for heating the return portion of the conveyor, said means including passages disposed under the forward end of the conveyor and in communication with the said gas circulating passages at the forward part of the muffle.

6. In a glass leer, a muffle, a conveyor having a portion extendin through the mufiie with the forward end 0 the conveyor entering the mufile a short distance back from the forward end of the mufile, whereby the mufllo overhangs the forward end of the conveyor, gas circulating chambers above and below the muffle, flues at the sides of the muffle connecting the upper and lower chambers, a substructure under the conveyor having a relatively wide circulating chamber at the forward end of the sub-structure, a passage leading from the wide circulating chamber through the sub-structure, a chimney, and a valve-controlled flue in communication with the last mentioned passage and the chimney.

7 In a glass leer, a mufiie, a conveyor having a portion extending through the muflie with the forward end of the conveyor entering the mufiie a short distance back from the forward end of the muflle, whereby the muflie overhangs the forward end of the conveyor, gas circulating chambers above and below the mufile, flues at the sides of the muffle connecting the upper and lower chambers, a substructure under the conveyor having a relatively wide circulating chamber at the forward end of the sub-structure, an extended floor portion projecting inwardly from the muffle, a chimney, a passage under the extended floor in communication with the relatively wide passage of the sub-structure, and a valve-controlled .flue in communication with the passage under the floor and the chimney.

' In testimony whereof I affix my signature.

WILLIAM A. MORTON. 

